Trudy Rubin | Decision time on the Islamic State

The beheading of a second American journalist on YouTube by Islamic State barbarians has finally focused U.S. attention on Syria.

The Islamic State’s sick, slick self-promotion — its global glorification of the murders of James Foley and Steven Sotloff — has done what 200,000 Syrian deaths and the growth of a new al-Qaida state failed to accomplish. The release of the Sotloff snuff video on Tuesday, two weeks after Foley’s death — with both men displaying incredible stoicism as their British-accented, masked murderer raised his knife — was like a punch to the American gut.

It brought home the risk of leaving these madmen free to develop their caliphate within huge chunks of Syria, even as U.S. airstrikes push back their efforts in Iraq.

Americans are boiling. Congress is outraged. Vice President Joe Biden proclaims, “We will follow them to the gates of hell until they are brought to justice.”

This is a teachable moment, when President Barack Obama could recoup from the recent “We don’t have a strategy yet” comment when asked about Syria. He could use these videos to illustrate the serious threat the Islamic State poses to Americans in the near term, a threat that could necessitate future U.S. airstrikes on Islamic State camps or movements in Syria.

Yet I already see this opportunity draining away.

Everything the president has said since the release of the videos, including remarks on his way to Thursday’s NATO summit in Wales, shows his reluctance to strike at the Islamic State safe haven in Syria.

I understand this reluctance. Americans are weary of involvement in more Mideast wars, even as they criticize Obama for not showing enough leadership in the region. So it’s not surprising that Obama is calling for a global coalition against terrorism, a theme he will promote at the United Nations General Assembly session this month (where Russia and China are likely to block anything he suggests).

Obama is also is sending Secretary of State John Kerry and Defense Secretary Chuck Hagel to the Mideast this week to encourage Arab nations to fight terrorists in their region.

These efforts are long overdue, but, unfortunately, they have their limits. Obama’s credibility among Mideast leaders is shot — in large part because of his famous reluctance to meet his own previous red lines and unleash promised air strikes after Syria’s leaders used poison gas.

Moreover, Mideast leaders are deeply divided, with the Sunnis of the Gulf lined up against Shiite leaders in Syria, Iraq and Iran. Without a convincing show of will in combating the Islamic State, Obama won’t be able to nudge Arab leaders to do more.

Indeed, Arab leaders are likely to pursue their own, often counterproductive efforts to confront the Islamic State, without listening to Kerry. He may make headway in some areas — such as pressing the Saudis to fund the desperate needs of refugees fleeing Syria and Iraq. He can also lean on the Saudis, along with Kuwait and Qatar, to block private funders of radical Islamist factions in Syria. The Islamic State is now self-funding, however, having raised hundreds of millions from extortion, seized oil wells and robbed banks.

In the end, Obama will have to decide if the Islamic State threat justifies unilateral U.S. action. He did unleash U.S. airstrikes in Iraq, after Islamic State fighters seized Iraq’s second largest city and was threatening America’s Iraqi Kurdish allies.

But the Kurds alone can’t push back the Islamic State, and the Iraqi army isn’t up to the job. Nor is a new Shiite-led Iraqi government likely to be inclusive enough to convince Sunni tribesmen to rebel against the Islamic State and risk having their heads cut off.

In Syria, Obama has been far more reluctant to use airstrikes, because there are no obvious allies — like Iraq’s Kurds — who could provide ground forces. Syria’s moderate Muslim and secular opposition militias have been decimated. And President Bashar Assad should not be enlisted as a partner. Not only is he a mass murderer, but he is also unwilling to confront the Islamic State.

So the president is confronted with a terrible dilemma. He said Wednesday that the U.S. objective is to “degrade and destroy (the Islamic State) so that it’s no longer a threat not just to Iraq but also to the region and to the United States.”

Yet a global antiterrorist coalition is an impossible dream. Arab leaders are too divided to unite against the threat. Obama must keep providing air cover in Iraq for the Kurds and any coherent Iraqi forces. But without degrading Islamic State training camps and movement in Syria with U.S. airstrikes, the group will continue to expand.

This means Obama must make a decision: He said Wednesday that before sending pilots to do a job, he should “know that this is a mission that’s going to work.” If by “work” he means destroying the Islamic State, then airstrikes are insufficient. But if Obama’s goal is to “degrade” the Islamic State and halt its momentum, then those strikes are essential.

Right now, the Islamic State is the hottest jihadi movement worldwide. Its videos help recruit thousands of Western volunteers, who can return home and wreak havoc. The deaths of Foley and Sotloff provide a gruesome warning that Islamic State aggression must be stopped.